Speaking ahead of the visit, Mr Hammond said: “Wherever we look, the world is becoming more dangerous and more uncertain.

“International engagement is fundamental to maintaining both Britain’s security and our prosperity.

“Britain’s strong relations with the Gulf states enable us to work together on regional challenges and shared threats that confront us, whether from violent extremism, terrorism, or volatile economic conditions.”

He said the Yemen crisis will be high on his agenda, saying that allowing the state to collapse “is simply not an option”.

Conflicts

In Syria, what began as a peaceful uprising against Syria’s President Bashar al-Assad five years ago became a full-scale civil war.

In the chaos, so-called Islamic State militants moved in over the border from Iraq and claimed territory.

More than 250,000 have people died in the conflict and 11 million made homeless.

The US, Russia, France and other world powers have entered the fray and the UK began air strikes targeting IS in Syria in December after MPs voted for action.

In Yemen, the main fight is between forces loyal to the beleaguered President, Abdrabbuh Mansour Hadi, and those allied to rebels known as Houthis, who forced Mr Hadi to flee the capital Sanaa in February 2015.

Houthis, also known as Ansar Allah (Partisans of God), adhere to a branch of Shia Islam known as Zaidism. They took control of Sanaa in 2014.

A coalition of Arab air forces, led by Saudi Arabia, began carrying out air strikes on the rebels in March 2015, saying it was “defending the legitimate government” of Mr Hadi.